Antenna Products

50:200 (4:1) CUBE™ Ladder line to Coax Balun, 1.8-30 MHz, 5 KW PEP

Similar in specifications to CB-4-1500 but
for 5KW PEP using special multi-core ferrite topology for increased
power output and wide impedance load range. Enclosure mounting feet on sides, choice of “N”(specify
if needed) or SO-239 (default) input connectors

Purpose. This impedance transformer is set up as a
balun (unbalanced coax to balanced 200 ohm output) and is designed to
convert from coaxial cable to ladder line up to 5KW PEP from 1.8 to 61
MHz. It provides conversion from unbalanced coax to balanced ladder line
and gives a 4:1 impedance step-down to reduce impedance seen by the
coax, allowing the tuner to easily match the antenna. This impedance
transformer consists of multiple cores of ferrite configured as a true
current balun giving well balanced currents into each output terminal
over a large range and providing a 4:1 step down from 100 – 600 ohms.
The 4:1 conversion ratios give input connector impedances in the range
of 17 – 150 ohms for loads of 100 – 600 ohms which yield SWR’s under 3:1
easily managed by most antenna tuners. Consider using this balun
primarily where brute force, high power capability is needed over a
range of output impedances such as a multiband Zepp fed ladder line
antenna.Application. A zepp dipole can be used as a multi-band
antenna by using an antenna tuner to convert the impedance to 50 ohms
for the transmitter. The zepp is usually fed with 300-600 ohm balanced
line feeders and, as long as the feed line length is an odd number of
1/8 wavelengths at the fundamental frequency (468/f (MHz), the impedance
at then end of the feeders will generally be in the 100-500 ohm range.
The CB-4-5000AT is designed to operate over a range of 100-600 ohms and
convert these ranges to 17-150 ohms impedance which can be easily
matched by an antenna tuner at the end of the coax. Coax length from the
balun to the antenna tuner should be kept to less than 10 feet due to
the potentially high SWR (and coax losses) that may occur on the coax.
Of course the ladder line changes the impedance seen at the balun
depending on its length. But there still is a wide range of impedances
seen from band to band and a very rugged balun, such as the CB-4-5000AT
is required to cope with it. The impedance conversion is almost uniform
for the 1.8-61 MHz range but is adequate for most tuners to match the
transmitter/transceiver. The CB-4-5000AT is best used for ladder line to
coax or as an antenna tuner balun for matching a broader range of load
impedances.
This product is NOT designed to be used with unbalanced outputs – use our 4:1 Unun’s for unbalanced output requirements.

For best results use a feed line choke on the coax input to suppress common mode currents.

Due to the multiple output options, these items are made to order, please allow 5-10 days shipping time.

$149.95In stock

MPN:CNB-4-5000AT

Frequency Band(s):160-6 meters

Input ohms/Output ohms:50 in, 200 out balanced

Frequency Range

PEP Power Rating (watts):5000

Input Connector
"N" Connector (0)
SO-239 Connector (0)

Palomar antenna products include feed line chokes, feed line to antenna matching transformers, static bleeders and other accessories. Click on the link to connect to the product you need.

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